Lost Tribes of the Green Sahara
How a dinosaur hunter uncovered the Sahara's strangest
Stone Age graveyard
On October 13, 2000, a small team of paleontologists led by Paul Sereno of the University of Chicago clambered out of three battered Land Rovers, filled their water bottles, and scattered on foot across the toffee-colored sands of the Ténéré desert in northern Niger. The Ténéré, on the southern flank of the Sahara, easily ranks among the most desolate landscapes on Earth. The Tuareg, turbaned nomads who for centuries have ruled this barren realm, refer to it as a "desert within a desert"—a California-size ocean of sand and rock, where a single massive dune might stretch a hundred miles, and the combination of 120-degree heat and inexorable winds can wick the water from a human body in less than a day. The harsh conditions, combined with intermittent conflict between the Tuareg and the Niger government, have kept the region largely unexplored.
Sereno, a National Geographic Society explorer-in-residence and one of the world's most prolific dinosaur hunters, had led his first expedition into the Ténéré five years earlier, after negotiating agreements with both the leader of a Tuareg rebel force and the Niger Ministry of Defense, allowing him safe passage to explore its fossil-rich deposits. That initial foray was followed by others, and each time his team emerged from the desert with the remains of exotic species, including Nigersaurus, a 500-toothed plant-eating dinosaur, and Sarcosuchus, an extinct crocodilian the size of a city bus. The 2000 expedition, however, was his most ambitious—three months scouring a 300-mile arc of the Ténéré, ending near Agadez, a medieval caravan town on the western lip of the desert. Already, his team members had excavated 20 tons of dinosaur bones and other prehistoric animals. But six weeks of hard labor in this brutal environment had worn them down. Most had mild cases of dysentery; several had lost so much weight they had to hitch up their trousers as they trudged over the soft sand; and everyone's nerves had been on edge since an encounter with armed bandits.
Mike Hettwer, a photographer accompanying the team, headed off by himself toward a trio of small dunes. He crested the first slope and stared in amazement. The dunes were spilling over with bones. He took a few shots with his digital camera and hurried back to the Land Rovers.
"I found some bones," Hettwer said, when the team had regrouped. "But they're not dinosaurs. They're human."
Heat, thirst, and, for the moment, dinosaurs were forgotten as the team members followed Hettwer back to the three dunes and began to gingerly survey their slopes. In just a few minutes they had counted dozens of human skeletons. Parts of skullcaps pushed up through the sand like upturned china bowls; jawbones clenched nearly full sets of teeth; a tiny hand, perhaps a child's, appeared to have floated up through the sand with all its finger bones intact. "It was as if the desert winds were pulling them from their final resting places," said Hettwer. Insinuated among the human bones was a profusion of clay potsherds, beads, and stone tools— finely worked arrowheads and axheads and well-worn grindstones. There were also hundreds of animal bones. In addition to antelope and giraffe, Sereno quickly recognized the remains of water-adapted creatures like crocodiles and hippos, then turtles, fish, and clams. "Everywhere you turned, there were bones belonging to animals that don't live in the desert," said Sereno. "I realized we were in the Green Sahara."
For much of the past 70,000 years, the Sahara has closely resembled the desert it is today. Some 12,000 years ago, however, a wobble in the Earth's axis and other factors caused Africa's seasonal monsoons to shift slightly north, bringing new rains to an area nearly the size of the contiguous United States. Lush watersheds stretched across the Sahara, from Egypt to Mauritania, drawing animal life and eventually people.
Archaeologists have inventoried the stone tools used by these early inhabitants and the patterns inscribed on their ceramics. They have also identified thousands of their rock engravings, which depict herds of ostriches, giraffes, and elephants. Some of the images suggest that along the way the people of the Green Sahara learned to domesticate cattle. But they remain veiled in mystery. Did they arrive here from the Mediterranean coast, central African jungles, or Nile Valley? Were they nomads, or did they stake out territories and build settlements? Did they trade with each other and intermarry, or did they wage war, or both? As the monsoons began to recede, how did they cope with a drying landscape? The only part of the story that then seems clear is that by some 3,500 years ago the desert had returned. The people vanished.
Seeking answers to such questions is normally the domain of anthropologists and archaeologists—not dinosaur hunters. But Sereno had become transfixed by the discovery. "There is something soul stirring about looking into the face of an ancient human skull and knowing this is my species," he said. Whenever he could steal a moment from his paleontological work, he pored through every scholarly publication he could find on the Green Saharans, tracked down the authors and badgered them with emails full of questions. Sometimes he would read all night before downing a cup of coffee and heading back to his lab. In 2003, during another dinosaur expedition in Niger, he took three days off to revisit the dunes and survey the site, counting at least 173 burials. To dig any deeper, however, would require more time, money, and expertise. (News Courtesy By : Nationalgeographic)